1. Field of the Invention
The invention relates to a chip card with a flexible card body and electrical components arranged in the card body.
2. The Prior Art
During the manufacture of chip cards of the type specified above, especially DIN/ISO chip card bodies, three different techniques are conventionally used to integrate components of complex electronic circuits in the card bodies.
The generally known chip card is the simplest example for an implantation of electronic components in a card body. In this case, the circuit-carrying silicon is glued to the underside of the substrate, bonded and potted. Through contacts to the upper side of the substrate allow electrical contact to a peripheral system, especially a card reader. This so-called chip module is finally implanted in a plastic card body. The card body is merely the carrier of the electronic system without its own electronic properties or functions.
Whereas with implantation the electronic components are visible from outside, a slightly changed situation arises for the manufacture of so-called contactless cards. In this case, the chip module should not be visible. For this purpose, an already equipped circuit carrier, which is especially equipped with an antenna and a chip, is laminated into the central card plane. The substrate of the circuit carrier generally consists of the same material as the remaining card body so that a largely homogeneous material bonding is achieved as a result of the lamination. Mainly thermoplastics are used here, such as polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), polycarbonate (PC) and polyethylene terephthalate (PET). In cases where substrate and card material have significantly different properties, so-called adhesion promoters are used with which at least one of the bonding partners is coated. In the lamination method different films are placed over one another in a defined sequence and fastened. This film stack is then laminated between two sheets under pressure and temperature to give an approximately homogeneous material. However, if large-area silicon chips, especially silicon chips having an area of more than 20 mm2 are to be processed, this is barely possible using the lamination method. Especially if other components are to be integrated, this would result in a very complex structure of substrates, core films, spacer films, adhesion promoters and similar.